Population density comparison of Daphnia pulex (Linnaeus, 1758) fed with bacteria obtained from Biofloc system

Abstract

The use of heterotrophic bacteria as only food source in cladocerans diet to make massive production cultures has been little studied. So, this experimental study used Daphnia pulex cultivated in triplicate in 20 L plastic beakers at 19°, 21° and 25 °C temperature, with continuous light and aeration (24 hours), during 60 days. The bacteria source was obtained from screened liquid (20 µm) grown in Biofloc tilapias system. Every third day a sample of 500 mL was taken from each beaker and all organisms were counted. The highest density was found at 19 °C experimental test but the organisms died on third day. The maximum density was obtained at 21°±2 °C was of 24,414±244 org, whereas, lower density was found at 25°±2 °C with 19 259±252 org. The ANOVA analysis showed significant (P